Centrifuge



Jan. 27, 1953 s. ABBOTT 2,626,746

CENTRIFUGE Filed Oct. 25, 1946 4 Sheets-Sheet 1 Java; Z; maeZ ,a

S. L. ABBOTT Jan. 27, 1953 CENTRIFUGE 4 Sheets-Sheet 3 Filed Oct. 251946 Jan. 27, 1953 s. ABBOTT 2,626,746

CENTRIFUGE Filed Oct. 25, 1946 4 Sheets-Sheet 4 Patented Jan. 27, 1953UNITED STATES PATENT OFFICE CENTRIFUGE Samuel L. Abbott, Wilton, N. H.

Application October 25, 1946, Serial No. 705,664

11 Claims. 1

This invention relates to a centrifuge of the type having a heavy liquidtherein adapted to control the discharge of a separated component whichhas been separated by the centrifuge. It has previously been proposed toprovide the container of a centrifuge with an annulus of a rela tivelyheavy liquid of specific gravity greater than that of the heavier of theseparated components, and to provide a disk or similar element extendinginto this liquid annulus so that the liquid annulus constitutes a sealconsisting in effect of two liquid columns. Both of such liquid columnsare subject to the action of centrifugal force, and the first or innerone of these columns is subject also to the pressure thereon of theheavier separated component within the container.

Such a construction embodying a liquid seal has the potential advantageof affording a Way in which the separated components exit from thecontainer can be controlled without provision, in the rotatingmechanism, of mechanical valves subjected to the destructive action ofthe separated component.

It is possible by suitable choice of the extent of penetration of thedisk or similar element into the liquid annulus to obtain a sufficientlydelicate balance between the net resistance to displacement of the twoliquid columns of the annulus and the pressure within the container thatthe separated component will be more or less continuously dischargedfrom the container through the liquid annulus. However, I havediscovered that when such a delicate balance is secured there is atendency for the liquid seal to separate the heavier component accordingto its particl size,

' discharging the finer particles of this heavier component whileholding back the larger particles and thus causing these largerparticles to accumulate in the container.

A principal object of the invention is to provide a centrifuge having aliquid seal adapted to control the discharge of a separated component,avoiding the disadvantages of prior liquid seals, and requiring, as theapparatus is set up for use, less delicate balance of the liquid columnsof the seal and the pressure within the container, or less accurateregulation of the extent of contact of the disk or similar element withthe liquid annulus.

'A further object is to provide for accurate regulation of the dischargeof a separated component from the container of the centrifuge while theapparatus is running.

Other objects of the invention and advantageous features will beapparent from this specification and its drawings wherein the inventionis described by way of example.

In the drawings:

Fig. 1 is a diagrammatic vertical cross sectional view of a centrifugeembodying this invention, the centrifuge being shown as rotating in theoperation of separating the material in the container into the lighterand heavier components, but this material being omitted from the figurefor clarity of illustration;

Fig. 2 is a right end elevation of the centrifuge of Fig. l with some ofthe parts omitted;

Fig. 3 is a diagrammatic view in the nature of j a vertical sectiontaken on the line 3-3 of Fig. 1 in one adjustment of the centrifuge;

Fig. 4 is a view similar to Fig. 3 showing a different adjustment of thecentrifuge;

Fig. 5 is a view similar to Fig. 1, showing an- 6 other form ofcentrifuge embodying the invention. In Fig. 5 the centrifuge, thoughshown as rotating, is shown as adjusted to shut off discharge of theheavier separated component which is omitted from this figure; and

Fig. 6 is a vertical cross sectional View of the right end of thecentrifuge of Fig. 5. to a larger scale, showing the heavier separatedcomponent and showing the centrifuge adjusted to cause discharge of thiscomponent.

The invention is applicable to the separation of various mixtures ofliquids, gases, solids and any of these.

described by way of example as applied to a centrifuge for separatingdirt from the other compo nents of wool scouring liquor.

It is an advantage of the invention that wool scouring liquor can beeffectively treated by the improved centrifuge even though the liquidcontains a larg quantity of dirt. It is thus unnecessary to employpreliminary settling of the liquor for the purpose of eliminating partof the dirt rotatable tubular shaft 2 which is mounted in ball bearings3 and 4 in a suitable frame indicated generally by the referencecharacter 5.

The container and its tubular shaft 2 may be I In this application theinvention will be mounted to rotate on whatever axis is desired, and byway of example, these are shown as mounted for rotation on a horizontalaxis. The container may be rotated through a pulley 2" at theappropriate speed.

A suitable casing substantially surrounding the rotating container isdivided into appropriate sections for reception of the separatedcomponents of the material as these leave the rotating container.

The container may have as many exits as there are components into whichit is desired to separate the material, for instance, there may be exitsadapted to discharge respectively the dirt, the water, and a mixture ofthe grease and fats, and the casing could then be provided with suitablecompartments for the reception of these separated components. Forsimplicity of illustration, the container is shown as provided withexits for the dirt on the one hand and for the water and grease and fatson the other hand, the casing including a compartment 9 for reception ofthe dirt and a compartment ID for reception of the water and grease andfats.

Thus one or more exits l I (one being shown in Fig. 1), locatedrelatively close to the axis of the container, discharge the water andgrease and fats into the compartment ID. The dirt is discharged into thecompartment 9 through a mercury seal at the larger diameter right-handportion of the container, more fully described below.

The material to be treated may be continuously fed into the containerthrough a stationary axially extending tube M. A vertical branch l ofthe tube [4, provided at its top with a funnel is and removable stopper[1 is adapted for use in supplying the sealing liquid to the containerat the beginning of a run, before material to be treated is fed inthrough the tube l4.

As shown in Fig. 1 the larger diameter righthand portion of thecontainer is shaped to provide an annular pocket 2!! adapted to hold thesealing liquid. The outer margin of the pocket 20' is defined by anannular rim portion 2| which is securely welded to the container at 2 lto prevent loss of the sealing liquid at this joint.

A generally circular barrier element 22 having for example a plate-likeform as shown in Fig. l is adapted to make contact with the annulus ofsealing liquid, and so prevent unrestricted exit of the material fromthe container.

Preferably the barrier element 22. is rotatably mounted, and as hereinillustrated, is shown as integral with a shaft 23 which rotates in ballbearings 24 and 25 carried by a housing 26 on a plate 21. Rotation ofthe barrier element is most easily obtained by merely allowing it to berotated by its frictional contact with the sealing liquid which in turnis rotated by the container.

The sealing liquid 35 which constitutes the annular seal in the pocket20 has a greater specific gravity than the heavier component which isseparated by the centrifuge, and in the typical case in which dirt isthe heavier component, this sealing liquid may consist of mercury,carbon tetrachloride, or other suitable liquid that is heavier than thedirt.

The portion of the liquid annulus lying inside or to the left of thebarrier element 22 of Fig. 1 constitutes in effect one liquid column 35and the portion of the sealing liquid that lies outside or to the rightof this barrierelement 22 constitutes in effect another liquid column35, and these two liquid columns react in the manner of the two liquidcolumns of a U-tube. Both liquid columns are subject to and tend to bedepressed by the action of centrifugal force, and inner column 35 butnot the outer column 35 is subject also to the depressing action thereonof the contents of the container. The height of the inner column 35 withrelation to the peripheral path of the barrier element determines at anygiven speed of rotation the amount of pressure that must be developedwithin the container in order to displace the inner face of the innercolumn radially outwardly to or slightly beyond the periphery of thebarrier element 22. With such displacement of the inner column theheavier separated component can work outwardly beyond the periphery ofthe barrier element 22, pass the barrier element 22, and then, becauseof lesser specific gravity than the sealing liquid, float inwardlyradially through the other column 35 Each of the illustrated embodimentsof the invention provide means operable during rotation of the containerand independently of the degree of pressure within the container, forcausing a relative lowering of the inner column of the sealing liquidwith relation to at least a portion of the barrier element, permittingdischarge of the separated component past the sealing liquid and barrierelement to be accurately regulated.

In the device of Figs. 1 to 4 such means involves provision forestablishing a non-concentric relation between the rotating containerand the barrier element. A relatively small amount of non-concentricityis effective for the purposes of this invention.

Referring to Figs. 1 and 2, the plate 27, carrying the bearings in whichthe barrier element rotates, carries a stud 29 adapted to rotate orpivot in a vertical portion of the frame 5. A handle 3| is fixed to astub shaft 32, rotatable in the frame 5 and carrying a pin 33 whichengages in a recess 34 in the plate 21. Tilting of the handle 3| willthus tilt the plate 21 slightly about the axis of stud 29 and thus causea relative displacement of the centers of the container and barrierelement.

In normal running, when the handle 3| is not engaged by the operator,the barrier element 22 assumes a concentric relation to the rotatingcontainer, as shown diagrammatically in Fig. 3. By means of the handle3| the barrier element 22 can be held in more or less non-concentricpositions with respect to the container, such for instance as showndiagrammatically in Fig. 4.

Although in its broader aspects the invention is not limited tooperating with such heightof sealing liquid with respect to the barrierelement as to prevent discharge of the heavier separated component whenthe container and barrier element are in their normal relativepositions, it is an advantage of the invention that it can be thus used.Thus in the device of Figs. 1 to 4, the amount of sealing liquid and theheight of its inner column with respect to the periphery of the barrierelement in normal running is preferably, although not necessarily,sufficient to prevent exit of the heavier separated component when thecontainer and barrier element are in their normal concentric relation.

Tilting of the handle 3! of the device of Figs. 1 to 4 then establishesa non-concentric relation between the container and barrier element,such for instance as diagrammatically shown in Fig. 4, with the resultthat in one are of the path of the annular sealing liquid the extent ofcontact of the barrier element with the sealing liquid is reduced andthere is thus a relative lowering of the level of the inner column 35with relation to -a portion of the path of the periphery of the barrierelement. When this "relative lowering has been carried far enough, theare where this takes place can then constitute a zone of continuous exitof the heavier separated component from the container. By suitableadjustment of the handle sufficient flow of the heavier separatedcomponent can be caused through this place of exit to insure departureof the entire heavier separated component without holding back thelarger sized particles of this heavier separated component.

All particles of the heavier separated component, urged by centrifugalforce against the wall of the container, come in turn to this place ofdischarge where the relative lowering of the inner column of liquid withrelation to the path of the periphery of the barrier element has takenplace. Thus, without the use of valves or unduly restricted passages,that are subject to becoming plugged by the material being separated,there is provided a place of discharge for the heavier separatedcomponent where this component may leave the container without anysubstantial tendency to be subdivided according to its particle size.

It should be understood that While Fig. 4 shows diagrammatically one ofthe possible non-concentric relations between the barrier element 22 andbowl I, this figure should not be taken as showing accurately the exactposition of the sealing liquid in the pocket of the container, becausethis is variable. Also some turbulence probably develops in the sealingliquid, especially in the region of the discharge of the heavierseparated component.

In the centrifuge of Figs. 5 and 6 the relative lowering of the innercolumn of sealing liquid is a relative lowering with respect to thewhole of the peripheral path of the barrier element, instead of only aportion of such path as in Figs. 1 to 4, and is brought about bytemporarily drawing off liquid from the inner column into the outercolumn. A preferred form of mechanism for this purpose includesprovision for causing a relative displacement of the barrier element andthe container for the sealing liquid in an axial direction.

The device of Figs. 5 and 6 includes many parts which are similar to andcorrespond to those of the device of Figs. 1 to 4, and theseparts ingeneral are indicated by the same reference characters With primes addedthereto.

In the device of Figs. 5 and 6 the container I" within the rotatingcontainer the right-hand or.

outer liquid column 35 of the sealing liquid.

The compartments 9 and I0 for the heavier and lighter separatedcomponents respectively, are shown as located at the opposite ends ofthe cylindrical container, to receive these respective components fromthe opening 40 in the righthand end of the container and from one ormore openings II in the left-hand end of the tainer.

The shaft'23" for the disk 22" which consti-" tutes the right-handbarrier element is extended throughout the length of the container andbe yond the both of its ends, and is provided with a passage 45 forentrance into the container of the material to be separated and also thebody of mercury or other sealing liquid that cooperates with the barrierelement 22'.

Shaft 23 of the device of Figs. 5 and 6 has its ball bearings 24 and 25'mounted, respectively, in slide blocks 54 and at the left and right endsof the frame.

A non-rotating collar 62, screw-threaded into the slide block 55,surrounds the right end of shaft 23' and holds a non-rotating tubeadapted to be connected to a supply of material to be separated, aspring 66 yieldingly holding the tube 65 against the hollow shaft 23'.The vertical tube I5, formed at its top as a funnel l6, and providedwith a removable stopper l1, communicates with tube 65 and hence withpassage 45 of shaft 2 to supply mercury to the interior of thecontainer.

A further barrier element, shown as a further disk 4'! is preferablyprovided near the left end of the container, fastened to the same shaft23' that holds the barrier element 22'. One or more holes 48, close tothe axis of rotation are provided in order to allow the lighterseparated component to pass the disk 41 on its way to the exit hole orholes ll. As shown in Fig. 5 the container is provided with an enlargedannular pocket 49 into which the periphery of the left barrier disk 41extends, and a further body of mercury or other sealing liquid 50 isprovided in the pocket 49 and cooperates with the disk 41 as a seal.This body of sealing liquid 50 is sufficiently large and the penetrationthereof of the disk Al is sufficiently deep so that during operation ofthe centrifuge no material escapes around the periphery of the disk 41,regardless of the adjustment of the apparatus. An annular shoulder 49(Fig. 5) separates the body of sealing liquid 50 from the inner column35 in all adjustments of the apparatus.

A non-rotating collar 12, screw-threaded into the slide block 54,surrounds the left end of shaft 23 and holds a non-rotating tube 15which is pressed by a spring 16 against the left end of shaft 23. Theleft end of shaft 23 is provided with a passage M5 communicating withthe interior of the container in the region of the pocket 49, and apassage 11 in the slide block 72, communicating with tube and passageM5, permits mercury to be supplied to the pocket 49 preparatory tooperating the centrifuge. The opening to passage ll may be closed by aremovable stopper (8 after the mercury has been supplied.

As in the device of Figs. 1 to 4, the barrier element 22 of Figs. 5 and6 is preferably allowed to rotate by its frictional engagement with thesealing liquid, and in this case the second disk 41 rotates, in asimilar manner.

A bell crank 60, pivotally mounted at 6| on the frame of the machine,has one of its arms forked to engage the collar 52 and the other arm ofbell crank 66 is shaped to provide a handle 63 by which the bell crankcan be turned by the operator and the slide block 55, shaft 23, the twobarrier elements 22' and 4'! and slide block 54 shifted lengthwise ofthe container.

In the normal running of the container the parts may for example havethe position shownin Fig. 5, in which the right-hand column .of-

liquid 35 is relatively narrow in axial extent, and the height of thesealing liquid constituting the inner column 35 is high enough withrespect to the periphery of disk 22 to prevent discharge of the heavierseparated component, for example the separated dirt.

Shifting the shaft 23 and the barrier element 22' to the left in thedevice of Fig. 5 tends to lower the level of the inner sealing liquidcolumn with relation to the periphery of the barrier disk 22', and uponsufficiently shifting the disk 22 to the left, for instance as to theposition shown in Fig. 6, the level of the inner column 35 is loweredsufficiently with relation to the periphery of the disk 22' to permitdischarge of the dirt D past the disk.

It will be understood that because the radially inner face of the innercolumn of sealing liquid is subject to the pressure of the contents ofthe container and the radially inner face of the outer column 35" is notsubject to the pressure of the contents of the container, the outercolumn 35*" will extend to a greater height than the inner column in alladjustments of the disk 22. Consequently when the disk 22 is shiftedover toward the left, the space for the right-hand or outer column 35 isenlarged in an axial direction, and sealing liquid will flow from theleft of the disk 22 over to the right of the disk 22'. The column 34 maytend to fall somewhat because the space at the right of the disk isincreased, but the height of column 35 will not fall below the height ofcolumn 35 because the pressure upon column 35 is larger than thepressure upon column 35 During the shifting of the disk 22 either to theleft or right, the other disk 41 shifts accordingly, but does not affectthe sealing liquid 35 the disk merely shifting back and forth in its ownbody of sealing liquid 50 which, as indicated above, is sufficientlydeep to prevent exit of material in any adjustment of the disks.

Preferably the hole or holes 48 for the passage of the lighter separatedcomponent through the disk 41 are relatively small, and offersubstantially more resistance to passage of this material than do thehole or holes H at the left end of the centrifuge container. With thisconstruction a material amount of the thrust of the container contentsagainst the right-hand disk 22 is counterbalanced by the thrust of thecontainer contents against the left-hand disk 47, thus materiallyreducing the axial thrust of the container against the lengthwiseshiftable barrier elements and shaft 23.

It will now be apparent that while I have shown in Figs. 1 to 4 a meansfor effecting a relative lowering of theinner column of sealing liquidby relative adjustment of the barrier element and container in adirection transverse to the axis of rotation, and I have shown in Figs.5 and 6 means for effecting a relative lowering of the inner column bydrawing on" liquid from this column into the outer column by relativeadjustment of the barrier element, the relative lowering could, ifdesired, be secured by a combination of these several means.

In either of the illustrated devices the centrifuge may be kept runningwith its container and barrier element appropriately adjusted to afforda continuous discharge of the heavier separated component, or the partsmay be restored to an adjustment such that the heavier separatedcomponent is not discharged, and then only adjusted to a dischargingrelation at intervals as desired.

If the amount of sealing liquid and height of the inner column thereofis sufficient to permit some continuous discharge of the heavierseparated component in the normal concentric adjustment of Figs. 1 to 4,or in the normal right-hand position of Figs; 5 and 6, intermittentadjustment of the parts to permit a greater discharge of the heavierseparated component will have the effect of flushing out anylargerparticle portions of the heavier separated component which mayhave been held back by the liquid seal in the adjustment permitting somecontinuous discharge.

For a given set of operating conditions the container and barrierelement may be fixed in their desired adjusted positions relative toeach other.

Also, while for convenience of construction of the apparatus, thebarrier element is preferably truly circular, as shown in the drawings,this is not essential to the broader aspects of the invention.

I claim:

1. A centrifuge comprising a rotatable container for receiving materialto be separated into components of different specific gravity, saidcontainer having an opening through which may be discharged a separatedcomponent, a seal'to obstruct exit of a separated component through thedischarge opening including a sealing liquid having a specific gravitygreater than that of the heaviest component to be separated, and abarrier element, marginal portions of which dip into the sealing liquiddefining connected inner and outer columns of the sealing liquid in thecontainer, the centrifuge including a conduit permitting entrance intothe container, on the inner side of the barrier element, of the materialto be separated, a central shaft for the barrier element, a mountingpermitting said shaft and barrier element to be shifted bodily relativeto a Wall of the container during rotation of the container to cause arelative lowering of the level of the inner column with relation to atleast a portion of the peripheral path of the barrier element, andoperating mechanism having a portion outside of the container and notpartaking of the rotation of the container, said operating mechanismbeing connected to said shaft to effect such shift of the barrierelement during rotation of the container.

2. A centrifuge comprising a rotatable container for receiving materialto be separated into components of different specific gravity, saidcontainer having an opening through which may be discharged a separatedcomponent, a seal to obstruct exit of a separated component through thedischarge opening including sealing liquid having a specific gravitygreater than that of the heaviest component to be separated, and arotatable barrier element, marginal portions of which dip into thesealing liquid defining connected inner and outer columns of the sealingliquid in the container, the centrifuge including a conduit permittingentrance into the container, on the inner side of the barrier element,of the material to be separated, a mounting for the container and amounting for the barrier element, one of said mountings being shiftablerelative to the other transversely of the axis of the rotatingcontainer, thus permitting a relative displacement of the axes ofrotation of the container and the barrier element to cause a relativelower- 9 ing of. the level of the inner column with relation to aportion of the peripheral path of the barrier element.

3. A centrifuge comprising a rotatable container for receiving materialto be separated into components of different specific gravity, said container, having an opening through which may be discharged a separatedcomponent, a seal to obstruct exit of a separated component through thedischarge opening including sealing liquid having a specific gravitygreater than that of the heaviest component to be separated, and abarrier element in contact with the sealing liquid, the centrifugeincluding a conduit permitting entrance into the container, on the innerside of the barrier element, of the material to be separated, a mountingfor the container and a mounting for the barrier element, one of saidmountings being shiftable relative to the other transversely of the axisof the rotating container, thus permitting a non-concentric relationbetween the rotatable container and the barrier element whereby theextent of contact of the barrier element with the sealing liquid isreduced in an arc of the path of the sealing liquid.

4. A centrifuge comprising a rotatable container for receiving materialto be separated into components of different specific gravity, saidcontainer having an opening through which may be discharged a separatedcomponent, a seal to obstruct exit of a separated component through theopening including sealing liquid having a specific gravity greater thanthat of the heaviest component to be separated, and a rotatable barrierelement in contact with the sealing liquid, the centrifuge including aconduit permitting entrance into the container, on the inner side of thebarrier element, of the material to be separated, a mounting for thecontainer and a mounting for the barrier element, one of said mountingsbeing shiftable relative to the other transversely of the axis of therotating container, thus permitting a non-concentric relation betweenthe rotatable container and the rotatable barrier element whereby theextent of contact of the barrier element with the sealing liquid isreduced in an arc of the path of the sealing liquid.

5. A centrifuge comprising a rotatable container for receiving materialto be separated into constituents of different specific gravity, saidcontainer having an opening through which may be discharged a separatedcomponent, a seal to obstruct exit of a separated component through thedischarge opening including sealing liquid having a specific gravitygreater than that of the heaviest component to be separated, a generallyannular pocket for the sealing liquid, and a generally circular barrierelement substantially penetrating the sealing liquid in said pocket, thecentrifuge including a conduit permitting entrance into the container,on the inner side of the barrier element, of the material to beseparated, a mounting for the container and a mounting for the barrierelement, and mechanism for shifting one of said mountings relative tothe other transversely of the axis of the container during rotation ofthe container to adjust the relation between the axis of the containerand the center of the barrier element.

6. A centrifuge comprising a rotatable container for receiving materialto be separated into components of different specific gravity, saidcontainer having an opening through which may be discharged a separatedcomponent, a seal to obstruct exit of a separated component through thedischarge opening including sealing liquid having a specific gravitygreater than that of the heaviest component to be separated, and arotatable barrier element, marginal portions of which dip into thesealing liquid defining connected inner and outer columns of the sealingliquid in the container, the centrifuge including a conduit permittingentrance into the container, on the inner side of the barrier element,of the material to be separated, a mounting for the container and amounting for the barrier element, the mounting for the barrier elementbeing shiftable transversely of the axis of the rotating container, thuspermitting a relative displacement of the axes of rotation of thecontainer and the barrier element to cause a relative lowering of thelevel of the inner column with relation to a portion of the peripheralpath of the barrier element.

'7. A centrifuge comprising a rotatable container for receiving materialto be separated into components of different specific gravity, saidcontainer having an opening through which may be discharged a separatedcomponent, a seal to obstruct exit of a separated component through thedischarge opening including a sealing liquid having a specific gravitygreater than that of the heaviest component to be separated, and abarrier element, marginal portions of which dip into the sealing liquiddefining connected inner and outer columns of the sealing liquid in thecontainer, the centrifuge including a conduit permitting entrance intothe container, on the inner side of the barrier element, of the materialto be separated, mountings for the container andfor the barrier elementpermitting a bodily shift of the barrier element relative to a wall ofthe container during rotation of the container to cause a relativelowering of the level of the inner column with relation to at least aportion of the peripheral path of the barrier element, and operatingmechanism having a portion outside of the container and not partaking ofthe rotation of the container, said operating mechanism being connectedto the barrier element to effect such shift during rotation of thecontainer.

8. The centrifuge of claim '7 in which the bodily shift of the barrierelement relative to the container is in the direction of the axes ofrotation of the container.

9. The centrifuge of claim 7 in which displacement of the barrierelement inwardly of the container increases the axial extent of theouter column and so permits a lowering of the height of the innercolumn.

10. The centrifuge of claim 9 in which the sealing liquid forms a liningfor the container, such lining constituting the inner column.

11. The centrifuge of claim '7 including a second barrier elementaxially spaced from the firstnamed barrier element and penetrating asecond, separate, body of sealing liquid, the two barrier elements beingsubject to the outward pressure of the contents of the container inopposite directions and being connected together so as to tend tobalance the axial thrusts upon the barrier elements.

SAMUEL L. ABBO'IT.

(References on following page) REFERENCES CITED Th fdllow ing rfr'ehcsare of record in the file of this patent:

UNITED STATES PATENTS Name Date Alford t a1. Dec. 29, 1903 Boss Sept. 2,1913 Crocker 'Sep't. 30,1913 Beach 'Nov. '2, 191 5 Sc hiffefle Jlily 11,I916 Sharpl'es July '3, 1917 Number Number

